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AJE. BRIGGS. Telephone and Miorophonefiwitches'. No. 235,066. PatentedDec. 7,1880.

Fig.1.

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P ERS PNOTO-UTNOGRAPHER, WASHINGTON n c UNTTED STATES PATENT FFIQEOARTHUR E. BRIGGS, OF CINCINNATI, OHIO, ASSIGNOR TO POST & (30., OF SAMEPLACE.

TELEPHONE AND MICROPHONE SWITCH.

SPECIFICATION forming part of Letters Patent No. 235,066, dated December7, 1880,

Application filed June 2, 1880.

IO others skilled in the art to which my invention relates to make anduse it, reference being had to the accompanying drawings, forming partof this specification, wherein Figure l is a plan view of a telephonecallbox with the cover open, and showing the se crecy-switch in thecircuit of the magnetogenerator, and Fig. 2 is a like view of the boxwith the cover closed.

Similar letters of reference in the several figures of the accompanyingdrawings denote the same parts.

My invent-ion relates to a switch for telephone and microphone lineswhich is operated by the weight of the telephone to throw the 2 latterout of the circuit, but adapted when the telephone is removed from it toconnect with the line on either side of the signal-box for the purposeof establishing communication between any two subscribers and preventing0 their conversation from being overheard on the line. I

The object of the invention is to simplify and improve the means bywhich the short circuit is made and broken, and by which the primarycircuit of the microphone is established and the secondary currentthereof put upon the main line through the telephone; and to this enditconsists in the peculiar form of the switch and the arrangement of thesprings with which it is thrown in contact to make the requisiteconnections.

Referring to the accompanying drawings, A represents the box containingthe magnetogenerator; B, the binding-posts for the linewires 0 andground-wire D, and having the cover hinged to one side by five hinges, EF G H I. The inner side of the cover carries the eleetro-magnets J, theswitch-springs K K, the break-spring L, and the anvil M, upon whichthefree end of the break-spring rests, in po- (NO model.)

sition to be operated by the push-button N projecting through to thefront of the cover.

The belLhammer is attached to the arma tureoftheelectro-magnet andextends through a slot in the cover to vibrate between two bells on theoutside of the cover, and thus sound a signal when the short circuit isbroken by the push-pin and the current thrown to the line. This shortcircuit is established by wires 0 0, connecting the poles of thegenerator with the break-spring and anvil through the hinges E F, andwhen this circuit is broken, by operating the push-button the current isthrown to the line on one side of the generator through one of thepole-wires and the line-wires G, joined to the upper box-hinge, E, andis thrown to the line on the opposite side of the genera tor through theother pole-wire, the electromagnets, and the wires connecting suchmagnets with the breakspring and outer switchspring, K, thence throughsaid switch-spring and along the switch andinner switehspring, K, to theother line-Wire O, which connects its binding-post with the latterspring and passes through the box-hinge G.

P is the microphone, and Q the battery, having their primary wires R Itconnected to two binding-posts, S S, in. the lower end of the box, saidposts being also connected by a con tinuation of said wires through thetwo lower box-hinges, H I, to the fixed ends of two flat convergingsprings, T T, on the box-cover below the head of the switch.

U is the telephone, connected by wires V V of the secondary circuit fromtwo bindingposts, W W, in the lower end of the box, one binding-postconnecting with a line-wire or groundwire, and the other, by acontinuation of wire V, extending to a third binding-post, W, thence tothe secondary coil of the microphone, and from the latter to one of thebinding-posts of the primary wire.

X is the switch, pivoted to the cover and constructed with two curvedtop wings, Y Y, on

a line with or above the pivot, and two smaller 9 side wings, Z Z, belowthe pivot. Its lower end is formed with a hook to support the telephone,and when the latter is suspended from it the top wings, Y Y, pass underand in contact with the switch-springs K K to complete the requisiteconnections for transmitting the signals to theline as the short circuitis broken.

After the call has been made and answered the telephone is removed fromthe switch and the latter swung to one side or the other to connect withthe called line and cut out the line with which no communication isdesired. In this position the switclrwings Y Y stand diagonally acrossthe box-cover, disconnected from the switch-spring K of the uncalledline, but connected one with the spring K of the called line andtheother with the microphonespring T, that stands diagonally opposite,While the wing Z, that projects from the upper side of the switch, isconnected with the other microphone-spring T, all as shown by dottedlines in Fig. 1.

The operation of swinging the switch connects the local or primarycircuit of the microphone and puts the secondary circuit through thetelephone and upon the main line in the required direction. To restorethe short circuit of the signal apparatus and cut out the microphone andtelephone, the latter is again hung upon the switch and forces it, bygravity, into an upright position. This construction of the switch andthe arrangement of its connecting-springs is much more simple than themechanism employed for similar purposes in the telephone apparatuscommonly in use, as it reduces the number ofconnections and saves theexpense of several platinum contact-surfaces.

The switch-springs K K and T T are broad and flat, and the wings of theswitch are beveled off so as to pass freely under them with a longrubbing pressure, and thereby insure aperlect electrical contact.

Having thus described my invention, what I claim is l. Thegravity-switch X, constructed with the double wings Y Y and Z Z, incombination with the switch-springs K K and T T and their connections,substantially as described, for the purpose specified.

2. In a telephone apparatus, the four-armed gravity-switch adapted tosupport a telephone whose weight holds the upper arms, Y Y, in contactwith the switch springs K K, and adapted when the telephone is removedto be swung to the right or left to disconnect the uncalled line andplace one arm in electrical connection with the called line and twoother arms in electrical connection with the microphone, to connect itsprimary circuit and put its secondary circuit through the telephone andupon the called line, substantially as described, for the purposespecified.

In testimony of which invention I have hereunto set my hand this 25thday of May, A. I). 1880.

ARTHUR E. BRIGGS.

Witnesses:

E. A. ELLsWoRTH, N. K. ELLsWoR'rH.

